<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script src="https://cdn.bootcss.com/jquery/3.2.1/core.js"></script>
</head>
<body>

<form action="login">
	<input type="text" name= "name" ></br>
		<input type="password" name= "psd" ></br>
			<input type="submit"></br>
</form>


<img id="img" src="user/check.jpg">  

<script type="text/javascript">


window.onload=function(){
	alert("hello");
	$("#img").on("click",function(){
		alert("click img");
		this.attr("src","user/check.jpg");
	});
};

</script>
</body>
</html>